I suspect the reason why there is a 'running clock' rule now is because too many times, the opposing coaches didn't see eye to eye on how many points were enough (or how many points were too many) - especially in rivalry games, or when the subs should start playing, or when timeouts should be called, or what plays are appropriate to run, etc. To a certain extent, the running clock rule was implemented to save a coach from his own pride. Remember a few years back? In the third quarter, running clock was "optional" for the team that was getting beat. It wasn't until the 4th quarter that it was mandatory. But, too many 'old school' coaches felt like agreeing to running clock in the 3rd quarter was a sign of weakness or, as you put it, throwing in the towel. So they refused to do it. And the 35 point differential at the beginning of the 3rd quarter turned into a 50+ differential by the time the 3rd quarter ended. Hurt egos are one thing. Hurt players are another story. I'm pretty sure that's why running clock now becomes mandatory at whatever point in the second half the difference becomes 35 or more. At that point, it's just a matter of getting the game over with a little sooner to protect the players. Oh, and it's worth noting that not all schools are as deep as others. Some schools are lucky to have a full squad of second-stringers.
One thing I will say about some of those 8A schools in the Orlando area is that they've either never had success or they have a student population that doesn't value football. Schools that tend to be large with a heavy population of Hispanic students tend to care more about soccer, baseball and basketball than football. It's mainly because their families didn't grow up watching football so it isn't as big of a deal. A great example is Poinciana. They are historically one of the worst football schools around but they won a State Championship in basketball a few years ago. So the athletes are on the campuses for sure. But if the programs have no history of success then the athletes see no reason to play.
Another factor is the laid-back transfer rules. Now, kids can essentially consolidate talent on teams. So that also adds to some of these massive blowouts - especially when districts consist of teams like Cypress Creek being made to play teams like Osceola and Lake Nona. Of course they'll get blown out. It's going to be like that for the foreseeable future though.
I'm not talking about a bunch of 1A schools being beat on by Madison County. The mismatches have been 8A teams playing in Central Florida (Orange and Seminole Counties). These schools have student populations of 4000+. If a coaching staff can't pull together a reasonably competitive team from that size student population, they are probably coaching the wrong sport. Good teams will get blown out occasionally, whether it be because of a off day, maybe too many turnovers, or just a better opponent that day. I'm sorry, but I'm old school. The running clock to my generation is like throwing in the towel. When the game gets that far out of hand, the opposing coaches should agree to put in the subs and let them finish the game. That way, the losing team can still leave at the end of the game with some pride.
That’s why I hate with a passion when teams intentionally schedule mismatch games. It’s bad for the starters because they don’t play after halftime. It’s bad for the fans because they most likely leave at halftime of a useless blowout, thus getting screwed out of half the game. And it’s bad for the losers because the coach set his team up for an impossible task, only to be humiliated by a superior opponent. It’s embarrassing and irresponsible to send a team out for slaughter.
The running clock is for the safety of the players. Most of the time, the Head Coach of the team who is trailing is the person most encouraging of the running clock. That Coach wants to get his players out in one piece in the fastest possible time. Scheduling could and should possibly be looked at to create better and more even matchups, and districts by factors other then Geography and population of the school. That might cut down on the amount of running clocks yearly in High School Football in the state of Florida. The purpose of High School Football is for the enjoyment and participation of the players, most of whom will not go on to play the sports anymore after they graduate from High School. Not to create entertaining matchups and pique the interest of posters to a High School Football message board.